There are many different situations in which it is necessary to position a body or object in a precisely determined three-dimensional relationship to another body or object. The present invention relates to a positioning mechanism in which two bodies may be quickly and easily secured together in a predetermined spatial relationship to each other, and may then be as quickly and easily separated.
In performing production processes, for example, it is often necessary to position a work piece in a precise spatial relationship to a machine or work station. The time element is important in production processes, and hence it is advantageous to employ mechanisms that can be quickly attached or detached.
A particular production technology in which the precise positioning of parts is very critical to success is in the manufacture of microelectronic circuits. In that industry it is the established practice to initially prepare a substrate of semiconductor material, and then perform a series of photolithographic and other operations upon the substrate in order to create a number of electronic circuits or "chips", as they are commonly called in the industry.
The substrate is initially in the form of a thin, flat sheet or wafer of material. It is moved through a series of work stations where a corresponding series of measurement, photolithographic, and other steps are performed on it. Then the completed product is cut into a number of "chips". The substrate or wafer may initially have a maximum dimension of several inches, which each individual "chip" cut from the substrate may have a maximum dimension of less than one inch. Since each "chip" may carry hundreds or even thousands of individual electronic circuit elements, it is readily apparent that the physical, chemical, and photographic procedures utilized in building up the structure of the "chip" must have the greatest precision as to dimensions and tolerances that can possibly be obtained.